• Title/Summary/Keyword: Road service quality

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A Study for Controlling Early-age Temperature Rise of the Concrete Pavement by Shadow Tent in Hot Weather Construction (차광막를 이용한 하절기 콘크리트포장의 초기온도 관리 방안연구)

  • Joh, Young-Oh;Kim, Hyung-Bae;Suh, Young-Chan;Ann, Sung-Soon
    • International Journal of Highway Engineering
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    • v.6 no.4 s.22
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    • pp.75-89
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    • 2004
  • Long term performance of concrete pavement significantly depends on the given construction and environmental condition. It means that random cracks and extreme crack width due to inappropriate quality control at the early age might lead to decreasing the pavement service life. The temperature and moisture during the construction, cement and aggregate types, curing condition are major components to affect the quality of the concrete pavement at the early age. First of all, the high temperature differential, that is made by increasing air temperature and the heat of cement hydration, is known as the major contributor to severe cracks. In this study, tent covering was used for controlling temperature of the concrete slab. The field measurement data indicates that the effect of the tent covering is very significant to decrease possibilities of random crack occurrence and curling stress and enhance the long-term concrete strength. HIPERPAV(High PERformance PAVing software), a program predicting the strength and stress of an earty-age concrete pavement (72 hour after placement), is used for simulating the effects of tent covering. The HIPERPAVE results showed that the section with the tent covering has higher reliability than the section without the tent covering by 22.5%. In details, reliability is increased 72.5% (without the tent covering) to 95% (with the tent covering).

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A Study on the Strategy to promote Geospatial Information Industry based on Users Requirements Analysis (수요자 요구 분석을 통한 공간정보산업 진흥 전략에 관한 연구 -전문가 설문조사를 중심으로-)

  • Seok, Sangmuk;Song, Ki Sung;Hwang, Jung Rae
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.7
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    • pp.400-409
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    • 2016
  • The geospatial information industry has the advantage of being able to converge with other industries to create new value. Therefore, efforts are underway to promote the growth of this dwindling national industry by endorsing policies and initiatives to promote its convergence with other industries. In this study, feedback was collected from experts in various fields through three rounds of polls using the Delphi method. The poll results were used to investigate the causes of hindrance to the growth of the geospatial information industry and to build a comprehensive solution to this problem. As a result, 27 strategies were constructed based on the users' requirements related to policy, data and service, including the demands for establishing public polling methods, enhancing data quality and advertisement. Since the coefficient of variance fell between 0.11 and 0.20 in the importance evaluation, an amicable consensus was reached between the experts. Considering that the convergence of industries is achieved through the integration of various types of technology and information, it is important to consider the requirements of users in different industries. In this respect, the results of this study will serve as a useful base for constructing mid-to-long term road maps to promote the development of the geospatial information industry.

Bond Characteristics at the Interface between HMA Surface and RCC Base (아스팔트 표층과 RCC 기층 계면에서의 부착특성 연구)

  • Hong, Ki;Kim, Young Kyu;Bae, Abraham;Lee, Seung Woo
    • International Journal of Highway Engineering
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    • v.19 no.6
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    • pp.37-46
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    • 2017
  • PURPOSES : A composite pavement utilizes both an asphalt surface and a concrete base. Typically, a concrete base layer provides structural capacity, while an asphalt surface layer provides smoothness and riding quality. This pavement type can be used in conjunction with rollercompacted concrete (RCC) pavement as a base layer due to its fast construction, economic efficiency, and structural performance. However, the service life and functionality of composite pavement may be reduced due to interfacial bond failure. Therefore, adequate interfacial bonding between the asphalt surface and the concrete base is essential to achieving monolithic behavior. The purpose of this study is to investigate the bond characteristics at the interface between asphalt (HMA; hot-mixed asphalt) and the RCC base. METHODS : This study was performed to determine the optimal type and application rate of tack coat material for RCC-base composite pavement. In addition, the core size effect, temperature condition, and bonding failure shape were analyzed to investigate the bonding characteristics at the interface between the RCC base and HMA surface. To evaluate the bond strength, a pull-off test was performed using different diameters of specimens such as 50 mm and 100 mm. Tack coat materials such as RSC-4 and BD-Coat were applied in amounts of 0.3, 0.5, 0.7, 0.9, and $1.1l/m^2$ to determine the optimal application rate. In order to evaluate the bond strength characteristics with temperature changes, a pull-off test was carried out at -15, 0, 20, and $40^{\circ}C$. In addition, the bond failure shapes were analyzed using an image analysis program after the pull-off tests were completed. RESULTS : The test results indicated that the optimal application rate of RSC-4 and BD-Coat were $0.8l/m^2$, $0.9l/m^2$, respectively. The core size effect was determined to be negligible because the bond strengths were similar in specimens with diameters of 50 mm and 100 mm. The bond strengths of RSC-4 and BD-Coat were found to decrease significantly when the temperature increased. As a result of the bonding failure shape in low-temperature conditions such as -15, 0, and $20^{\circ}C$, it was found that most of the debonding occurred at the interface between the tack coat and RCC surface. On the other hand, the interface between the HMA and tack coat was weaker than that between the tack coat and RCC at a high temperature of $40^{\circ}C$. CONCLUSIONS : This study suggested an optimal application rate of tack coat materials to apply to RCC-base composite pavement. The bond strengths at high temperatures were significantly lower than the required bond (tensile) strength of 0.4 MPa. It was known that the temperature was a critical factor affecting the bond strength at the interface of the RCC-base composite pavement.

Study on the Integration of MMS and Airborn Survey Data for the Implementation of Precise Road Spatial Database (정밀도로공간정보 구축을 위한 지상 MMS 측정자료와 항공측량자료의 결합방법 연구)

  • Hwang, Jin Sang;Kim, Jae Koo;Yun, Hong Sik;Jung, Woon Chul
    • Journal of Korean Society for Geospatial Information Science
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    • v.23 no.2
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    • pp.97-104
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    • 2015
  • Due to the introduction of various IT devices, including the recently smartphones and the widespread use of the car navigation system to the location-based information service space has been increased. Spatial information users have been requiring higher levels of quality. In this paper, we study how to build accurate three-dimensional space information by integrating MMS(Moblie Mapping System) survey and airborne survey data. Thus, to analyze the tendency of deviation between the MMS survey and airborne survey data observed in the experimental region, the deviation tendency of the data, it was confirmed that was not consistent. Deviation correction model to select how to change the georeferencing information directly contained in the GPS/INS processing results for the determination, classifies the standard is a method for acquiring the correction reference point coordinates using the calibration model, and analyzed their advantages and disadvantages. With the information of the reference point obtained by airborne photograph of a project, using the method of correcting the MMS survey data. Not only clear the deviation existing between the MMS survey data, it was possible to confirm that the deviation exists between the airborne survey data and MMS survey data was also almost erased.

An Estimation of Link Travel Time by Using BMS Data (BMS 데이터를 활용한 링크단위 여행시간 산출방안에 관한 연구)

  • Jeon, Ok-Hee;Ahn, Gye-Hyeong;Hyun, Cheol-Seung;Hong, Kyung-Sik;Kim, Hyun-Ju;Lee, Choul-Ki
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.13 no.3
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    • pp.78-88
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    • 2014
  • Now, UTIS collects and provides traffic information by building RSE 1,150(unit) and OBE about 51,000(vehicle). it's inevitable to enlarge traffic information sources which use to improve quality of UTIS traffic information for Stabilizing UTIS's service. but there are missing data sections. And, In this study as a way to overcome these problems, based on BIS(Bus information system) installed and operating in the capital area to develop normal vehicle's link transit time estimation model which is used realtime collecting BMS data, we'll utilize the model to provide missing data section's information. For these problem, we selected partial section of suwon-city, anyang-city followed by drive only way or not and conducted model estimating and verification each of BMS data and UTIS traffic information. Consequently, Case2,4,6,8 presented highly credibility between UTIS communication data and estimated value but In the Case 3,5 we determined to replace communication data of UTIS' missing data section too hard for large error. So we need to apply high credibility model formula adjusting road managing condition and the situation of object section.

A Study on the Causes and Improvement Plans for Firefighters' Casualty Accidents During Rescue Activities related to the Water - 4M Analysis - (수난구조활동 중 소방공무원 순직사고의 원인과 대응방안에 관한 연구 - 4M분석기법을 중심으로 -)

  • Park, Chanseok
    • Journal of the Society of Disaster Information
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    • v.17 no.4
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    • pp.710-721
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    • 2021
  • Purpose: The purpose of this study is to prepare an environment that can provide high-quality 119 rescue services by analyzing the causes of casualties at the water rescue and suggesting improvement plans to prevent them. Method: 5 major cases were analyzed among firefighters' casualty accidents during rescue activities related to the water over the past 10 years for case study. And the causes of the accidents were analyzed in terms of 4 values (Man, Machine, Media, Management) through the 4M analysis technique. Result: ① man: the main causes are lack of awareness of on-site safety, etc ② machine: the problem of the absence of the equipment itself, etc ③ media: the lack of information on the rescue site and the poor rescue environment conditions, ④ management : the main causes were the absence and inadequacy of the response manual for each rescue site, Conclusion: ① man: knowledge of SOP and reinforcement of education and training, etc. ② machine: there are measures such as the introduction of equipment suitable for the changing rescue site, ③media: providing sufficient information about the rescue activity environment and conducting regular road training, ④ management: policy suggestions such as establishment and dissemination of on-site safety management plans and manuals were derived.

A Study on the Location of Retail Trade in Kwangju-si and Its Inhabitants와 Effcient Utilization (광주시 소매업의 입지와 주민의 효율적 이용에 관한 연구)

  • ;Jeon, Kyung-sook
    • Journal of the Korean Geographical Society
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    • v.30 no.1
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    • pp.68-92
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    • 1995
  • Recentry the structure of the retail trade have been chanaed with its environmantal changes. Some studies may be necessary on the changing process of environment and fundamental structure analyses of the retail trade. This study analyzes the location of retail trades, inhabitants' behavior in retail tredes and their desirable utilization scheme of them in Kwangju-si. Some study methods, contents and coming-out results are as follows: 1. Retail trades can be classified into independent stores, chain-stores (supermarket, voluntary chain and frenchiise system and convenience store), department stores, cooperative associations, traditional, markets mail-order marketing, automatic vending and others by service levels, selling-items, prices, managements, methods of retailing and store or nonstore type. 2. In Kwangju, the environment of retail trades is related to the consumers of population structure: chanes in consumers pattern, trends toward agings and nuclear family, increase of leisur: time and female advances to society. Rapid structural shift in retail trade has also been occurred due to these social changes. Traditionl and premodern markets until 1970s altere to supermarkets or department stores in 1980s, and various types, large enterprises and foreign capitals came into being in 1990s. 3. The locational characteristics of retail trades are resulted from the spatial analysis of the total population distribution, and from the calculation of segregation index in the light of potential demand. The densely-populated areas occurs in newly-built apartment housing complex which is distributed with a ring-shaped pattern around the old urban core. The numbers and rates of the aged over sixty in Kwangsan-gu and the circumference area of Mt.Moodeung, are larger and higher where rural elements are remarkable. A relation between population distribution and retail trade are analysed by the index of population per shop. The index of the population number per shop is lower in urban center, as a whole, being more convenient for consumers. In newly-formed apartment complex areas, on the other, the index more than 1,000 per shop, meeting not the demands for consumers. Because both the younger and the aged are numerous in these areas, the retail trade pattern pertinent to both are needed. Urban fringes including Kwangsan-gu and the vicinity of Mt.Moodeung have some problems owing to the most of population number per shop (more than 1, 500) and the most extensive as well. 4. The regional characteristic of retail trade is analyzed through the location quotient of shops by locational patterns and centerality index. Chungkum-dong is the highest-order central place in CBD. It is the core of retail trades, which has higher-ordered specialty store including three big department stores, supermarkets and large stores. Taegum-dong, Chungsu-dong, Taeui-dong, and Numun-dong that are neiahbored to Chungkum-dong fall on the second group. They have a central commercial section where large chain stores, specialty shopping streets, narrow-line retailing shops (furniture, amusement service, and gallary), supermarkets and daily markets are located. The third group is formed on the axis of state roads linking to Naju-kun, Changseong-kun, Tamyang-kun, Hwasun-kun and forme-Songjeong-eup. It is related to newly, rising apartment housing complex along a trunk road, and characterized by markets and specialty stores. The fourth group has neibourhood-shopping centers including older residential area and Songjeong-eup area with independent stores and supermarkets as main retailing functions. The last group contains inner residential area and outer part of a city including Songjeong-eup. Outer part of miscellaneous shops being occasionally found is rural rather than urban (Fig. 7). 5. The residents' behaviors using retail trade are analyzed by factors of goods and facilities. Department stores are very high level in preference for higher-order shopping-goods such as clothes for full dress in view of both diversity and quality of goods(28.9%). But they have severe traffic congestions, and high competitions for market ranges caused by their sma . 64.0% of respondents make combined purpose trips together with banking and shopping. 6. For more efficiency of retail-trading, it is necessary to induce spatial distribution policy with regard to opportunity frequency of goods selection by central place, frontier regions and age groups. Also we must consider to analyze competition among different types of retail trade and analyze the consumption behaviors of working females and younger-aged groups, in aspects of time and space. Service improvement and the rationalization of management should be accomplished in such as cooperative location (situation) must be under consideration in relations to other functions such as finance, leisure & sports, and culture centers. Various service systems such as installment, credit card and peremium ticket, new used by enterprises, must also be carried service improvement. The rationalization and professionalization in for the commercial goods are bsically requested.

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The Introduction of archival science and the renovation of records Management(since 1999) (기록학의 도입과 기록관리혁신(1999년 이후))

  • Kim, Ik-Han
    • The Korean Journal of Archival Studies
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    • no.15
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    • pp.67-93
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    • 2007
  • This article deals with the short history from 1999 to the present time, how the Korean record and archives management world had grown up, and what the development of the branch of records and archives studies resulted in. First of all, it is looked out upon the transition and feature of each initiative bodies of records management, containing the records producing body, records and archives management body, records and archives professional body, and civil society. As a result, this article points out the disequilibrium state of the records producing body and civil society, for all the growth of records and archives management institutions and records and archives professionals. During the time of establishing the law, the Korean records and archives management had been made a rapid progress by some part of the leading group being to Korean Records and Archives Service and the society of professionals. But it is estimated only the malformed development depending on the model of elites, although we could achieve the establishment of Korean Records and Archives Act. The condition of records and archives management of the Participation Government was distinguish from the state of former times, being driven up the renovation of records and archives management. The main power of the renovation was sought our by overcome of the elite model with the development of archival institutions and professionals extending wide range. Particularly professionals to accept the education of graduate school grew up in quantity and quality and then they let the pattern of the collaboration with archival institutions rake root in Korea. As The Road Map on the Renovation of National Records and Archives Management was made, the government put into practice, so the management of records and archives in Korea could take a step of steady and continuous growth. But the development of the records producing bodies and civil society is staying at the low level as yet. Accordingly it is expected to have the most important means that the professional instruction become to normalize and archivists who posted in public agencies after graduating professional education program discharge their duties. And each public agencies have to speed up to set up the institutions for records management including some archivists so that overcome the condition of underdevelopment as fast as possible.

Mitigation of Insufficient Capacity Problems of Central Bus Stops by Controlling Effective Green Time (유효녹색시간 조정을 활용한 중앙버스정류장 용량 부족 완화 방안 연구)

  • Koo, Kyo Min;Lee, Jae Duk;Ahn, Se Young;Chang, Iljoon
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.21 no.1
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    • pp.35-50
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    • 2022
  • After the introduction of the central bus lane system, bus traffic was prioritized. This resulted in improved trust from bus users. However, the low capacity at the central bus stop reduces traffic speed and punctuality. In addition, physical constraints are inevitable because the construction of central bus lanes and bus stops considers the city's road geometry. Therefore, this study attempted to optimize the effective green time of the traffic signal system at the entrance and exit of the central bus stop to remedy its insufficient operational capacity. The Transit Capacity and Quality of Service Manual and Korea Highway Capacity Manual were used as the analysis methodologies. The number of stop areas for central bus stops to be built was determined by excluding variable physical factors, and field survey data collected from nine randomly selected central bus stops currently installed in Seoul were used. A scenario analysis was conducted on the central bus stops with insufficient capacity by adjusting the effective green time, and the capacity of the central bus stop was set as the dependent variable. According to the results, 26.7 percent of the central bus stops with insufficient capacity can solve the problem of insufficient capacity. Therefore, the results of this study can be verified by improving the operation level, and it can be effective even if the number of central bus stops calculated by engineering is not guaranteed during the planning stage of the central bus stop. As the number of central bus stops is expected to increase further as the number of central bus stops increases, it is necessary to improve the number of central bus stops. Therefore, it is hoped that the results presented in this study will be used as basic data for the improvement plan at the operational level before introducing the physical improvement plan.